1. Field of the Invention
The present invention relates in general to ceramic matrix composites, and in particular to ceramic matrix composites with integrated topcoat ceramic layers and the method and process for fabricating the matrix composites with the integrated topcoat layers.
2. Related Art
Composite material systems typically consist of reinforcement materials embedded within a matrix material, and processed to form a matrix composite. The composite consists of reinforcement materials such as particulates, whiskers or fibers embedded in matrix materials such as ceramics, polymers, or metals. The material constituents of matrix composites may be varied to provide tailored properties such as thermal or electrical conductivity, coefficient of thermal expansion, density and mechanical properties.
Ceramic composites are desirable for certain applications due to their light weight, superior thermal properties, and low coefficient of thermal expansion. Also, ceramic composites can be reinforced with fibers to improve mechanical properties, as well as other properties. These reinforced composites are ideal for high temperature strength, low density, and high oxidation resistance. As a result, fiber reinforced ceramic matrix composites have emerged as a promising class of materials for a number of demanding applications in aircraft, missiles and industrial systems.
However, fiber reinforced ceramic matrix composites may require other properties for additional applications. The surface of these composites are typically rough or porous, whereas precise surface features or replicated geometric shapes are desired in some applications. Therefore, to provide these additional uses, what is needed is a fiber reinforced ceramic matrix composite with an integrated topcoat, which imparts additional surface characteristics to the composite. What is further needed is a ceramic topcoat integrated with a ceramic matrix composite substrate that can maintain structural integrity by overcoming effects of thermal expansion mismatch between the topcoat and the substrate during both processing and service.
Whatever the merits of the above mentioned systems and methods, they do not achieve the benefits of the present invention.